* {
  margin: 0;
  padding: 0;
  text-decoration: none;
}
a {
  color: #444;
}
.preview {
  width: 998px;
  height: 200px;
  margin: 30px auto;
}
.preview img {
  width: 100%;
  height: 100%;
}
.dt-cat {
  width: 998px;
  height: 300px;
  border: 1px solid #e0e0e0;
  background-color: #fff;
  margin: 0 auto;
}
.dt-cat h2 {
  width: 100%;
  height: 30px;
  margin-bottom: 18px;
  line-height: 30px;
  text-align: center;
  font-size: 22px;
  font-weight: 700;
  color: #444;
}
.threeall {
  margin: 20px auto;
  width: 90%;
  height: 200px;
}
.threeall .three {
  width: 33%;
  height: 100%;
  float: left;
  border-right: 1px solid #666;
}
.dt-cat-nav {
  width: 118px;
  height: 40px;
  background-color: orange;
  margin-left: 131px;
}
.dt-cat-nav span {
  color: #777;
  line-height: 20px;
  font-size: 14px;
  display: block;
  height: 20px;
  padding-top: 10px;
}
.dt-cat-nav i {
  font-size: 18px;
  margin-left: 46px;
  margin-top: -18px;
  position: absolute;
}
.dt-cat-nav a {
  display: block;
  width: 36px;
  height: 21px;
  text-decoration: none;
  position: absolute;
  margin-left: 69px;
  margin-top: -20px;
  font-size: 14px;
  color: #777;
}
.box {
  position: relative;
  margin: 0 auto;
  width: 1000px;
}
.item {
  position: absolute;
}
.item img {
  width: 100%;
  height: 100%;
}
